Dr. Saguna Verma. Amanda Shell photo.
By Deborah Manog, UH Med Now
Dr. Saguna Verma, an Associate Professor in the Department of Tropical Medicine at the John A. Burns School of Medicine (JABSOM), was featured in January’s edition of Nature Medicine, one of the world’s most prestigious science journals. The University of Hawai’i Mānoa scientist is highlighted in the article “Puzzling over privilege: how the immune system protects — and fails — the testes.”
The article acknowledges the work of Dr. Verma and her research partners, who study the immune mechanisms that allow Zika virus to linger in the testicles, long after the symptoms have cleared and the virus can no longer be detected in the rest of the body.
In December 2016, Dr. Verma received the first U.S. Zika Response Grant in Hawai’i to explore how Zika virus spreads through unprotected sex. The research took on added urgency locally after public health officials reported the Zika epidemic being spread through infected mosquitoes in Palau, just 4,500 miles from Hawai’i.
Nature Medicine describes the testes as an immune privilege site, having a blood-testes-barrier that protects the developing spermatids from being damaged by the body’s normal inflammatory response against pathogens. Dr. Verma’s team found that Sertoli cells, which act as gatekeeper cells that protect spermatids, can be affected by the Zika virus, causing them to allow the virus to pass through the blood-testes-barrier and possibly infect the sperm cells. Verma’s research was recently published in the Journal of Virology (Oct 2017).
“Clinical data shows that infectious Zika virus can be sexually transmitted by men long after the virus is cleared from their blood,” said Dr. Verma. She believes that the breakdown of the barrier could allow Zika from elsewhere to enter the testes and infect developing sperm cells.
Unlike other immune privilege sites like the eyes and the brain, the testes seem to be largely understudied. This is most likely due to the fact that human testes are less readily available than other tissue types donated to research.
But Dr. Verma and her team are already one step ahead and advancing their research through a new collaboration with a group of clinicians at Wake Forest University in North Carolina, who have artificially grown “organoids”, three-dimensional cell masses that resemble and function like normal organs, using testes cells.
Together, the scientists are trying to to replicate the Zika virus in organoids, in the same way that it occurs in human cells. The ultimate goal would be to discover a way for antiviral drugs to successfully enter the immune privilege site and clear any persistent viral infection from the testes.
Dr. Verma hopes that the new collaboration and using organoids to study viruses can become a platform for future research, that extends beyond Zika and includes other viral diseases.
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UH Medical Researcher Studies Sexual Transmission of Zika Virus